Efficient Active Bragg Grating Tunable Filters

Abstract

Reflection, transmission and loss filters based on fiber Bragg gratings are key components in future wavelength division multiplexing telecommunication networks. A shift of the Bragg wavelength, λ B , can be achieved by applying a strain or heating the fiber section containing the grating [1]. Here we report on Bragg grating devices that use a thin metallic coating to directly heat the fiber or a piezoelectric coating to strain it. Such integrated tunable filter devices show DC tuning [2-5] and modulation capabilities with promise for enhanced efficiency, reduced size, and low electrical power consumption.